# All Questions

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### Find Missing numbers in the picture [closed]

Let see who can crack this. Find the missing numbers in the image. Explain the logic. Challenge for all masterminds
2k views

### Cut up a cheese cube into $6$ equal parts with $5$ slices

Bob has a cheese cube and wants to cut it up into exactly $6$ equal pieces for his guests. These guests are professional cheese connoisseurs who will complain if they get less than anyone else. Bob ...
489 views

### A Perfectly Primitive Parameter Permuter

A simple challenge for the mathematically inclined. Find a function $f\left( {{x_1},{x_2},{x_3},{x_4}} \right)$ such that \begin{gathered} f\left( {2,3,4,5} \right) = 1 \hfill \\ f\left( {1,3,4,...
3k views

### When you are sick you might have me, with a hand full of letters [closed]

I apologize in advance for the lack of rhymes (as it seems quite difficult here). I have instead added a lot of 'depth' to this riddle (which should be easily unwound once solved) - Hopefully it isn't ...
8k views

### Weighing an elephant [closed]

Here's another classic I couldn't find on the site: How can you determine the weight of an elephant without using a scale?
2k views

### Chocolate challenge

Jack has \$1000 and plans to buy chocolates for all that money. He finds out that his favourite chocolate sells for \$1, but there is a special offer: for every four wrappers he gives to the ...
1k views

### A riddle of many elements

First a sport some love, Though it drinks their blood. Named for just a seat, Though power is the key. Then the sound of metal, Slamming together in war. That of which there are five, Vying in the ...
3k views

### Name the 25 Ants

When solving the Contagious Ants on a Meterstick problem, puzzlers often overlook the fact that ants are sophisticated creatures with names, dreams, and personalities. ...
1k views

### Contagious ants on a stick

Twenty-five ants are scattered on a meter stick. At the same time, they each pick a random direction (east or west) and start marching at 1cm/second. Whenever two ants meet, they turn around. When an ...
2k views

### Identify the twins and cousins!

Let me tell you about four friends of mine. They're a close-knit bunch: two pairs of twins who are cousins to each other. The first guy is Adam. He's a devout Christian, going to church every week. ...
675 views

### I give you some metal, and you steal my name!

It was hard to expand on this riddle while maintaining the single rhymes, so it is much easier than expected to solve...Hopefully you enjoy the rhymes: I give you some metal, and you steal my name! ...
1k views

### The Twenty Doors! (ROOM 3)

This is part of The Twenty Doors series. The previous one is The Twenty Doors! (ROOM 2) The next one is The Twenty Doors (ROOM 4) When you finally realise that the cipher used in room 2 was the ...
3k views

### How do I force-quit the program?

My friend has been playing with a program he found. He enters a 5-digit number into the command line and receives another 5-digit number in return. However, after 20 or so entries, he's about done and ...
657 views

### Rearranging connected tiles

Sorry. The previously posted image contained a mistake. Tile D2 was shown with a 180 degree rotation. The image has now been corrected. This is a straight-forward arrangement puzzle. You are ...
972 views

### Here's precisely what I am not. Who am I?

At first I’m quite fun to be around, until I make some wrongful sound. Maybe it offends, maybe it’s rude but I conceal my true attitude. Reverse me and you’ve something new be it a weapon, or a ...
624 views

### Circular arrangement Puzzle

I was given this puzzle: Eight friends (Romil, Ramesh, Rakesh, Rohit, Rahul, Abhijeet, Abhishek and Anil) are sitting around a circular table, but not necessarily in the same order. Four of them ...
751 views

### Pretzel recipe with a twist

Browsing the geometry section in the local library you come across a flimsy book, seemingly misplaced: "The Pretzel Cookbook: Five More Patterns Using The Spoke Method" What's more, it's been ...
10k views

### A Water Jug Problem [duplicate]

Suppose you are given two jugs: a 4-gallon one and 3-gallon one, and neither has any markings on it. You have a pump that can be used to fill the jugs with water. What do you do so that exactly 2 ...
551 views

### Who's my friend?

I've got a friend who's a real great guy! He loves a drink. He'll help you change your car tyres. This one time, he met an alien and got a coat out of it. This other time, he got talking to a space ...
1k views

### How to check a partial sudoku solution

John has started a sudoku puzzle and shows me his completed work, asking whether he's made any errors. There are no obvious errors (a number repeated in a row or subgrid). I know of two ways to ...
950 views

### How to check a partial Einstein's-like-puzzle solution

John has started an Einstein's-like puzzle ("$n$ people of $n$ ages prefer $n$ foods, etc.; determine which is which from the following facts"), using a matrix for his work. He shows me his completed ...